I come looking for help. I have a P59 with 12592318 OS. I am looking for an OS from an earlier year that I can swap to. I am putting this P59 into a 2003 Silverado. If I run it as is, I can't get the battery light to go off. The alternator is charging, but the light is on, because I believe 2005 has the updated charging circuitry. I made the changes in the System tab to match that of a 2003, but the issue persists. Any help will be appreciated. Trying to do this without having to purchase any additional license. I feel like there has to be a way. perhaps swap to some rare 2005 OS, which will allow the swap to a 2004 OS. I have spent hours looking and trying combinations.